How to Prevent Macular Degeneration

Age-related macular degeneration (AMD), a common cause of vision loss in later life, should be diagnosed, treated, and monitored early to prevent severe vision loss. Your risk of AMD can be reduced with a few simple lifestyle modifications, including changes in diet, routine exercise, and quitting cigarettes.

This is especially important for people with a family history of AMD, in whom the disease occurs four times more frequently than the general population. By making seven simple changes in your life, you may be able to mitigate the risk of a disease that causes progressive and often irreversible retinal damage and vision loss.

Quit Smoking

Macular degeneration occurs when the outer layers of the retina, in the area called the macula, begin to wear down.

There are two forms of the disease: nonexudative (dry) AMD, characterized by the buildup of drusen, yellowish deposits that accumulate under the retina, ultimately resulting in the loss of the central field of vision, and exudative (wet) AMD, in which blood vessels under the retina begin to leak or bleed in the macula, causing central vision loss.

Smoking is a leading contributor to severe vision loss from AMD. It speeds the progression of the disease by as much as five-fold compared to non-smokers. Smoking also makes treatments less effective by increasing the level of oxidants in the bloodstream and eyes.

Smoking cessation is arguably the number one modifiable risk factor for people with AMD. No matter how long and heavily you smoked, quitting cigarettes progressively reduces your risk of AMD for each and every year you are without cigarettes.

Under the Affordable Care Act, smoking cessation aids are classified as Essential Health Benefits (EHBs) and may be fully covered by insurance. Options include:

• Chantix (varenicline)
• Nicotine gum
• Nicotine lozenges
• Nicotine nasal spray
• Nicotine patch
• Nicotine inhaler
• Zyban (bupropion)

If you are among the 92.5% of Americans who had an unsuccessful quit attempt in the past year, do not give up. Quitting may take time, but the benefits to your health and eyesight will be well worth it.

Maintain a Healthy Blood Pressure

Hypertension (high blood pressure) promotes AMD by restricting blood to the vascular layer of the eye called the choroid. The loss of oxygen to the eye not only accelerates the progression of AMD but more than doubles the risk of wet AMD and central vision loss.

Studies have shown that the use of beta-blockers, angiotensin-converting enzyme (ACE) inhibitors. and angiotensin II receptor blockers (ARBs) may reduce the risk of early and intermediate (dry) AMD by as much as 25% and the risk of late (wet) AMD by 23%. This effect seems stronger when antihypertensive drugs are used in combination rather than on their own.

In addition to antihypertensive medications, there are lifestyle changes that can significantly reduce blood pressure as well. These include weight loss and routine exercise, particularly in people who are overweight or obese. Although weight in and of itself does not increase the risk of AMD, having a body mass index of 30 or more can increase the severity of the disease.

Weight loss of between 5 and 10 pounds can reduce the systolic blood pressure by 3 to 8 mm Hg in people who are overweight. Similarly, aerobic exercise performed 150 minutes a week can reduce blood pressure by 5 to 7 mm Hg.

If you don't know where to start with a weight loss plan, speak to a healthcare provider or ask for a referral to a certain dietitian or nutritionist. Quitting cigarettes can also significantly reduce blood pressure.

Increase Antioxidants in Your Diet

Antioxidants are substances that prevent or slow damage to cells caused by free radicals. Free radicals harm cells through a process known as oxidation (in which healthy molecules are destabilized as their electrons are replaced with oxygen).

Antioxidants reduce oxidative stress by "donating" electrons to free radicals, leaving normal cells untouched. With AMD, the retina is susceptible to oxidative stress because of its high consumption of oxygen (via blood vessels in the choroid).

For reasons not entirely clear, people with AMD experience greater oxidative stress not only in the eyes but throughout the body (as measured by levels of carbon and other byproducts of oxidation in the bloodstream). Over time, the stress not only causes irreversible injury to the macula but impairs the body's ability to clear damaged cells from the eye (referred to as autophagy).

It has been proposed that a diet rich in antioxidant foods can help minimize macular degeneration in some people. These include foods that are high in carotenoids like lutein and zeaxanthin as well as flavonoids like anthocyanin.

Among the foods with the highest antioxidant content are:

• Dark green leafy vegetables (like kale, Swiss chard, spinach, collard greens, mustard greens, and turnip greens)
• Green peas
• Summer squash
• Pumpkin
• Brussel sprouts
• Broccoli
• Asparagus
• Romaine lettuce
• Carrots
• Pistachios

While studies have yet to show a direct association between specific foods and the risk of AMD, epidemiologic research strongly suggests that antioxidant-rich Asian diets can significantly lower the risk.

A 2019 review of studies in the journal Nutrients concluded that Chinese are 50% less likely than Americans to develop wet AMD, due in part to their high intake of carotenoid-rich foods.

Take a Daily Supplement

Foods are not the only sources of antioxidants beneficial to people with AMD. Research conducted by the National Eye Institute (NEI) has suggested that certain dietary supplements can slow or stop the progression of early or intermediate AMD when taken daily.

Two trials conducted by the NEI, called the Age-Related Eye Disease Studies (AREDS) 1 and 2, explored whether specific vitamins and minerals could slow or prevent the progression of AMD.

The AREDS1 trial, which involved 4,457 participants, reported that a specific blend of antioxidants and minerals reduced the risk of late AMD by 25%. The formulation consisted of:

• Beta-carotene: 15 milligrams (mg)
• Copper (cupric oxide): 2 mg
• Vitamin C: 500 mg
• Vitamin E: 400 international units (IU)
• Zinc (zinc oxide): 80 mg

The AREDS2 trial, consisting of 3,529 participants, found that the addition of lutein (10 mg) and zeaxanthin (2 mg) further reduced the risk by 10% and 25% respectively.

This "recipe" has been used by manufacturers to create nutritional supplements specifically for people with or at risk of AMD. These include brands such as Alcon I-Caps AREDS 2, Bausch + Lomb PreserVision AREDS 2, Eyepex Macula, and ScienceBased Health MacularProtect Complete AREDS2.

Cut Back on Carbs

Eating fewer simple carbohydrates may help slow or stop the progression of AMD. Simple carbohydrates, which include white sugar and refined flour, have a high glycemic index (GI) and cause the blood sugar to spike and then plummet rapidly once consumed. These dramatic fluctuations trigger extreme inflammation throughout the body, which can remain chronic if simple carbs are eaten regularly.

A 2012 review of studies published in Molecular Aspects of Medicine concluded that a high GI diet not only increases the risk of AMD by as much 1.7 fold but also increases the likelihood of developing late AMD by 39%. By contrast, eating a low GI diet confers a lower risk of AMD and AMD progression.

Switching from simple carbs to complex carbohydrates is one of the easiest ways to reduce your risk of AMD. Complex carbs are rich in fiber and are metabolized more slowly in the intestines, avoiding extreme fluctuations in blood sugar levels.

Among the complex carbs you should incorporate in your diet are:

• Whole grains, such as barley, quinoa, buckwheat, and whole-wheat bread and pasta
• Fiber-rich fruits, such as apples, bananas, and berries
• Fiber-rich vegetables, such as leafy greens, broccoli, corn, and carrots
• Beans and legumes, such as lentils, chickpeas, and kidney beans

Among the simple carbs you should avoid are:

• Sugar, including brown sugar, raw sugar, and anything with high-fructose corn syrup
• Sodas and sweetened drinks
• Fruit juice concentrate
• Pastries and cookies
• White bread
• Ice cream
• Candy and desserts
• Most breakfast cereals

To aid in food selection, look for foods with a low GI label on the packaging or download a GI calculator app onto your cell phone.

Wear Sunglasses

There is little evidence that sun exposure increases the risk of getting AMD. But intense and ongoing exposure to ultraviolet (UV) radiation from the sun can cause retinal damage that not only accelerates the progression of the disease but contributes to the formation of cataracts.

To reduce the risk, the American Macular Degeneration Foundation (AMDF) recommends that you wear sunglasses with a UV 400 rating. A UV 400 rating ensures that all light rays with wavelengths up to 400 nanometers are blocked, reducing UV exposure by around 99%.

There are both tinted and clear UV 400 eyewear, the best of which wrap around the face to prevent rays from seeping in from the sides. Optometrists often refer to these as "cocoon glasses."

Another one of the most harmful bands of light on the visible spectrum is blue light. Blue light is emitted from both the sun and electronic devices like computers and digital TVs.

There is some evidence that high-intensity blue light emitted by LED screens can damage the eyes, although few computers emit the intensity (greater than 3 microwatts) needed to inflict harm.

Even so, some experts recommend that you minimize the use of electronic devices at night and use approved anti-blue-light glasses or screen covers if you have AMD.

Get Your Eyes Checked

Regular eye exams should be considered a routine part of your health care as you get older. Doing so can help healthcare providers spot the early signs of macular degeneration (including the formation of deposits, called drusen, in the retina). Eye exams can also look for any deterioration in your vision if you have AMD.

One way to tell if you need an eye exam is to perform a self-help test called the Amsler grid. The test, in which you stare at a 4-inch by 4-inch grid, may suggest that you have AMD if the lines look wavy to you or you notice dark areas in the central field of vision. In addition to detecting AMD, the Amsler grid can be used daily to monitor vision in people with AMD.

If AMD is suspected, an eye specialist called an ophthalmologist can perform a series of exams to diagnose the disease, including:

• Autofluorescence, a non-invasive test to for function of the retinal pigment epithelium, the layer of cells underneath the retina.
• Ophthalmoscopy, performed after eye dilation to visually examine the retina, choroid, and blood vessels
• Digital retinal imaging, which uses a specialized camera to take up-close images of the retina and macula
• Fluorescein angiography, using an injectable fluorescent dye to detect leaky blood vessels in people with wet AMD
• Optical coherence tomography (OCT) a non-invasive, in-office test that uses a laser light to detect retinal thinning, atrophy, and signs of both wet and dry AMD.

For many people, knowing one's AMD status provides the incentive needed to make important changes to one's life, including smoking cessation, improved diet and exercise, and weight loss.

Age-related macular degeneration is a disease that is as much influenced by lifestyle as your underlying genetics. As such, the choices you make and the habits you form can greatly alter your risk of AMD.

In the end, there are no real drawbacks to quitting cigarettes, maintaining a healthy weight and blood pressure, or reducing your consumption of simple carbs. All of these things are beneficial to your health whether you have AMD or not.

If you do have AMD, these simple changes can go a long way toward preventing disease complications.